1. Field of the Invention
This invention relates to a recording apparatus which is capable of recording a moving image and a still image on the same recording medium.
2. Description of the Related Art
A demand for high-density recording has recently increased in the field of magnetic recording. Video tape recorders (hereinafter referred to as VTRs) also have come to be arranged to perform recording with a higher density by lowering the traveling speed of the tape.
However, in a case where an audio signal is to be recorded with a stationary head, for example, the reduction of the tape travel speed brings forth a problem that the quality of reproduced sounds is degraded because it is impossible to have the sufficiently high relative speed of a tape to the head. According to one of known methods for solving this problem, the length of recording tracks to be scanned by a rotary head is extended to be longer than the conventional length and audio signals which are time-base-compressed are recorded one after another in the extension parts of the tracks.
More specifically, in the case of a VTR of the rotary-two-head helical scanning type, the VTR has been arranged to have a magnetic tape wrapped at least 180 degrees around a rotary cylinder. Whereas, in accordance with this method, the magnetic tape is arranged to be wrapped at least (180+.theta.) degrees around a rotary cylinder and an audio signal which has been subjected to a PCM (pulse-code modulation) process and time-base-compressed is recorded in the area of ".theta." degrees (hereinafter referred to as a PCM audio signal area or a PCM area).
FIG. 1 shows the tape transport system of the above-stated VTR. FIG. 2 shows the recording tracks formed on the magnetic tape by the arrangement of the VTR shown in FIG. 1. In FIGS. 1 and 2, reference numeral 6 denotes the magnetic tape. Reference numeral 18 denotes the rotary cylinder. Heads 5A and 5B are mounted on the rotary cylinder 18. A video signal area 19 and a PCM audio signal area 20 are formed in each of the recording tracks formed on the magnetic tape 6. The heads 5A and 5B are arranged to trace the video signal area 19 within the angle range of 180 degrees around the rotary cylinder 18 and the PCM audio signal area 20 within the angle range of .theta. degrees around the rotary cylinder 18.
As one example of an application of the above-stated method of recording the digital signal in the different area while the video signal is being recorded, a method for recording a still image digital signal within the digital signal area 20 has been proposed. In the case of a still image, one picture of still image information is completely recordable on the magnetic tape by using the PCM areas of a plurality of recording tracks.
This method not only permits the use of the same apparatus and the same recording medium both for taking a moving image and for taking a still image but also gives the still image with a higher grade of picture quality than a still image obtained by stopping the tape from traveling and by reproducing a video signal recorded in the same track formed on the tape.
However, in accordance with the above-stated example of the prior art method, a still image being taken cannot be monitored in recording the still image. It is, therefore, impossible to let the operator know the timing of the still image recording. It is also impossible for the operator to know the brightness and color tones of the still image being taken.
A further problem of the prior art method lies in that the recording time changes with variations in compression rate and bit rate set for the process of still image recording. Therefore, it is impossible to grasp the length of time required for the completion of the still image recording. It is thus hardly possible, for example, to find appropriate timing for bringing the still image recording action to an end and to determine release timing for a next still image recording process.